Galvanometek support



Aug. 7, 1951 c. M. HATHAWAY GALVANOMETER SUPPORT Filed Jan. 15, 1947Patented Aug. 7, 1951 UNITED STATES PATENT" OFFICE- GALVANO ETER SUPPORT7 Claude M. Hathaway, Denver, Colo.

Application January 13, 1947, Serial No. 721,801

2 Claims. (01. 17195) The present invention relates to galvanometer 4elements, and more particularly to a support structure for galvanometerelements of the multi-filar type.

Heretofore the construction of a bi=fil-ar it galvanometer elementemployed a base with spaced apart posts or supports each having aplurality of slots milled therein. In these slots a relatively flatsuspension ribbon was stretched with a mirror or reflecting surfacesuspended between the two supports by the fiat wire. In the past thesesupports have been made of ivory with two milled. slots about .004 inchwide. In order to support the mirror in a plane parallel to thesupporting base of the element great care must be taken to mill each ofthe slots exactly the same depth. Care must also be taken to have thecorners sharp so as to avoid a radius which might engage the fiatgalvanometer wire. Such construction requires a great deal of precisionwork with careful inspection which makes these posts rather expensive tomanufacture. It therefore would be desirable to provide some other formof construction which would obviate some of the disadvantagesencountered up to the present time.

In accordance with the present invention the ivory supports of abi-filar galvanometer may be manufactured much more economically and yetthe desired accuracy can be obtained. This is accomplished by mounting around ivory pin transversely of the slot to support the wire strips sothat they will not be bent as is the case in the prior construction.

It therefore is an object of the present invention to provide animproved galvanometer support which is relatively simple and economicalto manufacture.

A further object of the present invention is to provide an improvedbi-filar galvanometer element support which will permit a greatertension to be applied to the galvanometer wire.

Other and further objects of the present invention subsequently willbecome apparent by reference to the following description taken inconjunction with the accompanying drawing wherein:

Fig. 1 is a plan view of a bi-filar galvanometer element embodying thepresent invention;

Fig. 2 is an end view of the element shown in Fig. 1;

Fig. 3 is a detailed end view of one of the support posts shown in Figs.1 and 2; and

Fig. 4 is a side view of the details shown in Fig. 3.

Referring more particularly to Figs. 1 and 2 of the drawing it will beseen that the galvanom} eter element includes a support plate H whichcarries at one end a binding post l2 having one extremity extendingthrough an insulating bushing l3. At an intermediate point the supportplate II is provided with an aperture [4 which is adapted to receive agalvanometer lens. Adjacent the other end of the plate ii there ismounted a housing l5 having a cap l6.v The housing I5 contains anadjusting element H which acts against a spring l8 which in turn isconnected to a bell crank lever l9.

Mounted on one side of the plate I I are a pair of ivory support posts2! which carry a bi-filar element 22 having a mirror 23' attached in theproximity of the aperture I l. One end of the wire of the bi-filargalvanometer element 22 is connected to the binding post i2. The wireextends then to a pulley 24 carried by the bell crank l9 whereupon thewire returns over the support posts 2| to a fastening stud or post 25.The construotion thus far described is similar to the conventionalbi-filar galvanometer now in common use.

In accordance with the present invention, as shown in Figs. 3 and 4, thesupport posts 2| are provided with parallel milled slots 26 which extendappreciably below the level at which the galvanometer wires 22 aresupported. Transversely to and intersecting with the slots 26 a hole 27is drilled into which is fitted a cylindrical ivory pin 28. Thecylindrical ivory pin 28 supports the wires 22 and provides a sharpcorner between the walls of the slots 26 and the pin 28. Thus the pin 28assures parallel level positioning of the wires 22. The pin 28furthermore has the advantage illustrated in Fig. 4 of reducing thestrain on the wire 22 as it passes over the support posts to the pulleyor to the binding post and the fastening stud. By reducing the sharpnessof the change of direction of the wire a lesser strain is introducedinto the wire at the support rod 23 so that if desired a greater tensionmay be applied to the bi-filar galvanometer wire 22.

While for the purpose of illustrating and describing the presentinvention, a preferred embodiment has been illustrated in the drawing,it is to be understood that the invention is not to be limited therebysince such variations in the construction employed are contemplated asmay be commensurate with the spirit and scope of the invention as setforth in the following claims.

What I desire to protect by United States Letters Patent is claimed:

1. A galvanometer element comprising an elongated base, a pair of spacedapart insulated supports mounted thereon, each support having at its toptwo parallel recesses and a cylindrical opening arranged transversely tosaid recesses and intersecting with the lower portion thereof, acylindrical insulating member fitting into said opening to providecurved support surfaces of equal elevation within said recesses, a fiatwire having its ends fixed adjacent one of said supports and forming aloop intermediate its ends, said wire being positioned in the recessesof said supports, and adjustable means adjacent the other supportincluding a movable pulley for the intermediate loop of said wire forapplying tension thereto.

2. A galvanometer element comprising an elongated base, a pair of spacedapart insulated supports mounted thereon, each support having at its toptwo parallel recesses and a cylindrical opening arranged transversely tosaid recesses and intersecting with the lower portion thereof, acylindrical insulating member fitted into said opening to provide curvedsupport surfaces of equal elevation within said recesses, a flat wirehaving its ends fixed adjacent one of said supports and forming a loopbeyond the other of said supports, said wire being positioned in therecesses of said supports whereby the major portion of said wire isarranged in two parallel lines in a common plane, and adjustable meansengaging said wire loop for applying tension thereto.

CLAUDE M. HATHAWAY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 973,846 Bendel Oct. 25, 19101,933,252 Gent Oct. 31, 1933 2,065,907 Perreault Dec. 29, 1936 2,108,815Gilli et al Feb. 22, 1938 2,241,284 Walder May 6, 1941 2,368,831Hathaway Feb. 6, 1945 2,425,408 Williams, Jr., et a1. Aug. 12, 19472,465,082 Geiser Mar. 22, 1949

